1. Field of the Invention
The present invention relates to a method of making a semiconductor optical integrated device.
2. Description of the Related Art
To date, semiconductor optical integrated devices having a butt joint structure have been known. For example, Japanese Unexamined Patent Application Publication No. 7-263655 describes a semiconductor optical integrated device including a semiconductor laser and an electro-absorption (EA) modulator. The semiconductor laser and the electro-absorption (EA) modulator are optically coupled to each other through a butt joint and integrated with each other on a single substrate.